Add guidelines for C# development and MAUI patterns

instructions/blazor.md

@@ -23,7 +23,7 @@ appliesTo: "**/*.razor, **/*.cs"
 - Use data binding effectively with @bind.
 - Leverage Dependency Injection for services in Blazor.
 - Structure Blazor components and services following Separation of Concerns.
-- Use C# 10+ features like record types, pattern matching, and global usings.
+- Always use the latest version C#, currently C# 13 features like record types, pattern matching, and global usings.
 
 ## Error Handling and Validation
 

instructions/csharp.md

@@ -0,0 +1,113 @@
+---
+description: Guidelines for building C# applications
+---
+
+# C# Development
+
+## C# Instructions
+- Always use the latest version C#, currently C# 13 features.
+- Write clear and concise comments for each function.
+
+## General Instructions
+- Make only high confidence suggestions when reviewing code changes.
+- Write code with good maintainability practices, including comments on why certain design decisions were made.
+- Handle edge cases and write clear exception handling.
+- For libraries or external dependencies, mention their usage and purpose in comments.
+
+## Naming Conventions
+
+- Follow PascalCase for component names, method names, and public members.
+- Use camelCase for private fields and local variables.
+- Prefix interface names with "I" (e.g., IUserService).
+
+## Formatting
+
+- Apply code-formatting style defined in `.editorconfig`.
+- Prefer file-scoped namespace declarations and single-line using directives.
+- Insert a newline before the opening curly brace of any code block (e.g., after `if`, `for`, `while`, `foreach`, `using`, `try`, etc.).
+- Ensure that the final return statement of a method is on its own line.
+- Use pattern matching and switch expressions wherever possible.
+- Use `nameof` instead of string literals when referring to member names.
+- Ensure that XML doc comments are created for any public APIs. When applicable, include `<example>` and `<code>` documentation in the comments.
+
+## Project Setup and Structure
+
+- Guide users through creating a new .NET project with the appropriate templates.
+- Explain the purpose of each generated file and folder to build understanding of the project structure.
+- Demonstrate how to organize code using feature folders or domain-driven design principles.
+- Show proper separation of concerns with models, services, and data access layers.
+- Explain the Program.cs and configuration system in ASP.NET Core 9 including environment-specific settings.
+
+## Nullable Reference Types
+
+- Declare variables non-nullable, and check for `null` at entry points.
+- Always use `is null` or `is not null` instead of `== null` or `!= null`.
+- Trust the C# null annotations and don't add null checks when the type system says a value cannot be null.
+
+## Data Access Patterns
+
+- Guide the implementation of a data access layer using Entity Framework Core.
+- Explain different options (SQL Server, SQLite, In-Memory) for development and production.
+- Demonstrate repository pattern implementation and when it's beneficial.
+- Show how to implement database migrations and data seeding.
+- Explain efficient query patterns to avoid common performance issues.
+
+## Authentication and Authorization
+
+- Guide users through implementing authentication using JWT Bearer tokens.
+- Explain OAuth 2.0 and OpenID Connect concepts as they relate to ASP.NET Core.
+- Show how to implement role-based and policy-based authorization.
+- Demonstrate integration with Microsoft Entra ID (formerly Azure AD).
+- Explain how to secure both controller-based and Minimal APIs consistently.
+
+## Validation and Error Handling
+
+- Guide the implementation of model validation using data annotations and FluentValidation.
+- Explain the validation pipeline and how to customize validation responses.
+- Demonstrate a global exception handling strategy using middleware.
+- Show how to create consistent error responses across the API.
+- Explain problem details (RFC 7807) implementation for standardized error responses.
+
+## API Versioning and Documentation
+
+- Guide users through implementing and explaining API versioning strategies.
+- Demonstrate Swagger/OpenAPI implementation with proper documentation.
+- Show how to document endpoints, parameters, responses, and authentication.
+- Explain versioning in both controller-based and Minimal APIs.
+- Guide users on creating meaningful API documentation that helps consumers.
+
+## Logging and Monitoring
+
+- Guide the implementation of structured logging using Serilog or other providers.
+- Explain the logging levels and when to use each.
+- Demonstrate integration with Application Insights for telemetry collection.
+- Show how to implement custom telemetry and correlation IDs for request tracking.
+- Explain how to monitor API performance, errors, and usage patterns.
+
+## Testing
+
+- Always include test cases for critical paths of the application.
+- Guide users through creating unit tests.
+- Do not emit "Act", "Arrange" or "Assert" comments.
+- Copy existing style in nearby files for test method names and capitalization.
+- Explain integration testing approaches for API endpoints.
+- Demonstrate how to mock dependencies for effective testing.
+- Show how to test authentication and authorization logic.
+- Explain test-driven development principles as applied to API development.
+
+## Performance Optimization
+
+- Guide users on implementing caching strategies (in-memory, distributed, response caching).
+- Explain asynchronous programming patterns and why they matter for API performance.
+- Demonstrate pagination, filtering, and sorting for large data sets.
+- Show how to implement compression and other performance optimizations.
+- Explain how to measure and benchmark API performance.
+
+## Deployment and DevOps
+
+- Guide users through containerizing their API using .NET's built-in container support (`dotnet publish --os linux --arch x64 -p:PublishProfile=DefaultContainer`).
+- Explain the differences between manual Dockerfile creation and .NET's container publishing features.
+- Explain CI/CD pipelines for NET applications.
+- Demonstrate deployment to Azure App Service, Azure Container Apps, or other hosting options.
+- Show how to implement health checks and readiness probes.
+- Explain environment-specific configurations for different deployment stages.

instructions/dotnet-maui.md

@@ -0,0 +1,67 @@
+---
+description: MAUI component and application patterns
+appliesTo: "**/*.xaml, **/*.cs"
+---
+
+## MAUI Code Style and Structure
+
+- Write idiomatic and efficient MAUI and C# code.
+- Follow .NET and MAUI conventions.
+- Prefer inline functions for smaller components but separate complex logic into code-behind or service classes.
+- Async/await should be used where applicable to ensure non-blocking UI operations.
+
+## Naming Conventions
+
+- Follow PascalCase for component names, method names, and public members.
+- Use camelCase for private fields and local variables.
+- Prefix interface names with "I" (e.g., IUserService).
+
+## MAUI and .NET Specific Guidelines
+
+- Utilize MAUI's built-in features for component lifecycle (e.g. OnAppearing, OnDisappearing).
+- Use data binding effectively with {Binding}.
+- Structure MAUI components and services following Separation of Concerns.
+- Always use the latest version C#, currently C# 13 features like record types, pattern matching, and global usings.
+
+## Error Handling and Validation
+
+- Implement proper error handling for MAUI pages and API calls.
+- Use logging for error tracking in the backend and consider capturing UI-level errors in MAUI with tools like MAUI Community Toolkit's Logger.
+- Implement validation using FluentValidation or DataAnnotations in forms.
+
+## MAUI API and Performance Optimization
+
+- Utilize MAUI's built-in features for component lifecycle (e.g. OnAppearing, OnDisappearing).
+- Use asynchronous methods (async/await) for API calls or UI actions that could block the main thread.
+- Optimize MAUI components by reducing unnecessary renders and using OnPropertyChanged() efficiently.
+- Minimize the component render tree by avoiding re-renders unless necessary, using BatchBegin() and BatchCommit() where appropriate.
+
+## Caching Strategies
+
+- Implement in-memory caching for frequently used data, especially for MAUI apps. Use IMemoryCache for lightweight caching solutions.
+- Consider Distributed Cache strategies (like Redis or SQL Server Cache) for larger applications that need shared state across multiple users or clients.
+- Cache API calls by storing responses to avoid redundant calls when data is unlikely to change, thus improving the user experience.
+
+## State Management Libraries
+
+- Use dependency injection and the .NET MAUI Community Toolkit for state sharing across components.
+
+## API Design and Integration
+
+- Use HttpClient or other appropriate services to communicate with external APIs or your own backend.
+- Implement error handling for API calls using try-catch and provide proper user feedback in the UI.
+
+## Testing and Debugging
+
+- Test components and services using xUnit, NUnit, or MSTest.
+- Use Moq or NSubstitute for mocking dependencies during tests.
+
+## Security and Authentication
+
+- Implement Authentication and Authorization in the MAUI app where necessary using OAuth or JWT tokens for API authentication.
+- Use HTTPS for all web communication and ensure proper CORS policies are implemented.
+
+## API Documentation and Swagger
+
+- Use Swagger/OpenAPI for API documentation for your backend API services.
+- Ensure XML documentation for models and API methods for enhancing Swagger documentation.